MR image time-intensity relations in spleen and kidney: a comparative study of GdDTPA, albumin-(GdDTPA), and Gd2O3 colloid.
Magnetic resonance images were performed using a gradient recalled echo sequence with acquisition of images every 30 s in anesthetized rats before and after intravenous bolus injections of 100 microns/kg GdDTPA, 60 microns/kg albumin-(GdDTPA), and 60 microns/kg Gd2O3 colloid. All three agents caused significant enhancement of the renal cortex, and even greater enhancement of the spleen. GdDTPA showed an early peak at 11 s followed by a wash-out as blood concentrations fell, whereas albumin-(GdDTPA) and Gd2O3 showed sustained tissue enhancement. The enhancement in each organ was equivalent for albumin-(GdDTPA) and Gd2O3 which stay intravascular; but 30% less for GdDTPA which enters the interstitial space. In addition GdDTPA showed an initial enhancement of the renal medulla but then a subsequent loss of signal, whereas albumin-(GdDTPA) resulted in a greater enhancement of the medulla as compared to the cortex. We conclude that time-intensity studies of local tissue response to MR indicators reflect tissue physiological parameters such as perfusion, blood volume, and concentrating ability in a semiquantitative manner.
Daly
P F
PF
Pittsburgh NMR Institute, University of Pittsburgh, Pennsylvania 15213.
Zimmerman
J B
JB
Cannillo
J A
JA
Wolf
G L
GL
D000418:Albumins; D000818:Animals; D003102:Colloids; D003287:Contrast Media; D005682:Gadolinium; D019786:Gadolinium DTPA; D007668:Kidney / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging; D009942:Organometallic Compounds; D004369:Pentetic Acid; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000033:anatomy & histology*; D013997:Time Factors
D000418:Albumins; D003102:Colloids; D003287:Contrast Media; D009942:Organometallic Compounds; C058946:albumin-(gadolinium-DTPA); C030581:gadolinium oxide; D004369:Pentetic Acid; D005682:Gadolinium; D019786:Gadolinium DTPA